	<script type="text/javascript">
		// <![CDATA[
			function openWindow(url,width,height,options,name) {
				width = width ? width : 800;
				height = height ? height : 600;
				options = options ? options : 'resizable=yes';
				name = name ? name : 'openWindow';
				window.open(
					url,
					name,
					'screenX='+(screen.width-width)/2+',screenY='+(screen.height-height)/2+',width='+width+',height='+height+','+options
				)
			}
		// ]]>
	</script>

<a href="chat/" onclick="openWindow(this.href);this.blur();return false;">Chat</a>

<a href="chat/" onclick="openWindow(this.href,1024,768);this.blur();return false;">Chat</a>